ES2307627T3 - CINC ELECTRODEPOSITION AND CINC ALLOCATION PROCEDURES. - Google Patents

Abstract

Method of preparing an alkaline bath medium of zinc electrodeposition or zinc alloy, comprising the following steps: (A) preparing a random copolymer additive comprising a reaction product of: (i) one or more diterciary amines which they contain an amide or thioamide functional group, wherein said one or more diterciary amines are selected from the group consisting of N, N '' - bis [2-diethylaminoethyl] urea and N, N '' - bis- [3- (dimethylamino) propyl] urea; (ii) one or more second diteriary amines comprising an unsaturated moiety, selected from the group consisting of N, N, N '', N '' - tetramethyl-1,4-phenylenediamine, 4.4 '' - methylenebis- N, N-dimethylbencenamine, N, N, N '', N '' - tetramethyl-3,3 '' - sulfonylbisbencenamine, and 2,6-bis [(dimethylamino) methyl] -4-methylanisola, or a reaction product of one or more second diteriary amines that include a secondary amine group together with an unsaturated compound that can react with the secondary amine group to produce a pendant unsaturated group, the reaction product being selected from the group consisting of N, N, N '', N '' -tetramethyldiethylenetriamine reacted with benzyl chloride, 3,3''-imino-bis- (N, N-dimethylaminopropylamine) reacted with metalyl chloride, allyl glycidyl ether, or benzyl chloride, and N, N, N '', N '' - tetramethyldiethylenetriamine reacted with allyl chloride, with (iii) one or more binding agents that can react with said one or more amines d iterciary and said one or more second dimeric amines, or the reaction product of said one or more diteriary amines that include a secondary amine group together with an unsaturated compound, wherein said one or more binding agents are selected from the group consisting of epichlorohydrin, unsaturated compounds selected from the group consisting of 1,4-dichlorobutene, 1,4-dichlorobutino, and alpha, alpha '' '' - dichloro-p-xylene, and saturated compounds selected from the group consisting of 1,3-dichlorobutane, 1,4-dichlorobutane, 1,5-dichloropentane, 1,6-dibromohexane, and bis-2-chloroethyl ether; and (B) combining the reaction product of step (A) with a source of zinc ions and, in the case of the alloy, a source of additional metal ions of the alloy metals and a suitable chelating agent to make the ions soluble in order to produce an alkaline bath medium of zinc electrodeposition or zinc alloy.

Description

Zinc electrodeposition procedures and zinc alloy

The present invention generally relates to improvements in the electroplating of zinc and alloys of zinc from alkaline aqueous deposition baths, as well as to new additives for use in such procedures electrodeposition

The electrodeposition of zinc and alloys of zinc, for example based on sodium cincato, is known from years ago It is not possible to produce a deposit commercially acceptable from a simple electrolyte of sodium cincato, since that said deposit is powdery and dendritic. For this reason, it have proposed various additives in order to provide a improved deposition, such as cyanides (which present obvious environmental problems) and polymers of amines and epichlorohydrin which act as grain refinement additives. These polymers are limited to use in bathrooms that have concentrations relatively low zinc, since it is not possible to prevent a uncontrolled zinc deposition for concentrations greater than metal. In addition, the electrodeposition procedures they use these additives tend to have low cathodic efficacy, a narrow brightness range and a narrow operating window, and they tend to produce chopped and "burned" deposits.

More recently, additives have been proposed that allow the use of higher concentrations of zinc, which have significantly reduced burning and stinging and They allow a wider range of operating parameters. Further, these additives allow an excellent distribution of the tank (it is that is, the homogeneity of the deposit throughout the article that is subjected to electrodeposition, regardless of its shape in zones private individuals) This maximizes the effectiveness of zinc utilization. Generally, these additives are based on amine compounds polyquaternary, and are described in US Patent Nos. 5,435,898 and US No. 5,405,523, which also provide additional exposure About the prior art.

US Patent No. 5,435,898 describes polymers for use as additives in zinc electrodeposition and zinc alloys, said polymers having the formula general:

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one

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in which R_ {1} to R_ {4} can be identical or different and are, inter alia, methyl, ethyl or isopropyl, and Y can be S or O. R 5 is an ether bond, such how (CH 2) 2 -O- (CH 2) 2.

US Patent No. 5,405,523 claims polymers of quaternary ammonium ureylene in general as gloss agents in Zinc alloy electrodeposition baths. Polymers Preferred and indicated as examples include units of General Formula:

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2

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in which A can be O, S or N, and R it can be, among others, methyl, ethyl or isopropyl. In the polymers preferred, these units are linked by units derived, for example, from a bis (2-haloethyl) ether, a (halomethyl) oxirane or a 2,2 '- (ethylenedioxy) -diethylhalide. I also know suggest, although not indicated as examples, ethylene dihalides, such as ethylene dichloride and dibromide of ethylene.

Other known additives are the compositions polycationic based on the polymerization of ammonium chloride and dimethyl diallyl with sulfur dioxide, as described in DE 19,509,713.

However, the overall cathodic efficacy of These procedures can be low and the resulting deposits they can be unsatisfactory in terms of brightness and homogeneity.

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A recent patent application, published as WO00 / 50669, it discloses improved polymers for its use as additives in zinc electrodeposition and zinc alloys In particular, this request suggests that avoiding an ether type bond, such as R 5 in the art above described above, you can get one more deposit bright to which, in addition, it is easier to apply later conversion coatings.

Another very desirable aspect of the zinc electrodeposition is that the adhesion of the deposit The substrate must be excellent. This is because zinc has a very low permeability to hydrogen. In this way, the hydrogen, which is absorbed by the substrate (particularly in steel) during the deposition process, it can accumulate subsequently at the interface between the substrate and the coating, leading to the formation of "blisters." This formation of Blisters may appear when using additives according with the prior art described above.

WO 00/14305 describes polymers of General Formula:

3

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Applicants have investigated polymers of this type as electrodeposition additives and have discovered that the overall cathodic efficiency remains low and the resistance of the resulting deposit to blister formation after deposition It is still relatively low.

Accordingly, the present invention addresses of electrodeposition on a variety of substrates electrically conductive in a medium in order to provide improved cathodic efficiency and / or brightness and homogeneity improved, as well as to disclose resistant coatings formation of "blisters" after deposition. Substrates Suitable include iron and ferrous substrates (including iron alloys and steels), aluminum and its alloys, magnesium and its alloys, copper and its alloys, nickel and its alloys, and Zinc and its alloys. Aluminum and its alloys and substrates ferrous are particularly preferred substrates, the most preferred steels.

According to the invention, a procedure for preparing an alkaline bath medium of zinc electrodeposition or zinc alloy, which comprises steps of: (A) preparing a random copolymer additive that comprises a reaction product of: (i) one or more amines diterciary containing an amide or thioamide functional group, selecting the amine or diterciary amines from the group Constituted by N, N'-bis [2-diethylaminoethyl] urea  Y N, N'-bis- [3- (dimethylamino) propyl] urea; (ii) one or more second diterciary amines comprising a residue unsaturated, selected from the group consisting of N, N, N ', N'-tetramethyl-1,4-phenylenediamine, 4,4'-methylenebis-N, N-dimethylbencenamine, N, N, N ', N'-tetramethyl-3,3'-sulfonylbisbencenamine, Y 2,6-bis [(dimethylamino) methyl] -4-methylanisola, or a reaction product of one or more second dimer amines which include a secondary amine group together with a compound unsaturated that can react with the secondary amine group to produce a pendant unsaturated group, selecting the reaction product from the group consisting of N, N, N '', N '' - reacted tetramethyldiethylenetriamine with benzyl chloride, 3,3'-imino-bis- (N, N-dimethylaminopropylamine) reacted with metalyl chloride, allyl glycidyl ether, or chloride of benzyl, and N, N, N '', N '' - tetramethyldiethylenetriamine reacted with allyl chloride, with (iii) one or more agents binders that can react with the amine or diterciary amines and the second or second dimeric amines, or the product of reaction of the second or second diterciary amines that include a secondary amine group together with an unsaturated compound, selecting the binding agent or agents from the group consisting of epichlorohydrin, selected unsaturated compounds from among the group consisting of 1,4-dichlorobutene, 1,4-dichlorobutino, and α, α'-dichloro-p-xylene, and saturated compounds selected from the group constituted by 1,3-dichlorobutane, 1,4-dichlorobutane, 1,5-dichloropentane, 1,6-dibromohexane, and bis-2-chloroethyl ether; and (B) combine the reaction product of step (A) with an ion source zinc and, in the case of the alloy, a source of metal ions additional alloy metals and a chelating agent suitable for returning soluble ions in order to produce a Alkaline bath medium of zinc electrodeposition or alloy zinc.

In this report, unless the text otherwise require, "unsaturated" compounds include aromatic compounds, and "lower alkyl" means alkyls C_ {1} -C_ {6}.

In an embodiment of the first aspect of the invention, the first binding agent may also include a unsaturated rest.

Although it is preferred to use a single chemical substance for each of the respective components defined above, mixtures of the themselves in order to achieve the desired properties for the product, as long as the product includes unsaturation required

In an embodiment particularly preferred, the diterciary amine containing a functional group Amide or thioamide has the general formula:

4

and in which Y = O or S, a is an integer between 2 and 6, B represents a lower alkyl group and R represents a methyl, ethyl, isopropyl group, n-propyl or hydroxyethyl, and each R can be identical or different. R is preferably methyl, B is preferably a C2-C4 alkyl group, and more preferably it is C3.

They are examples of this type of diterciary amines N, N'-bis [2-diethylaminoethyl] urea Y N, N'-bis- [3- (dimethylamino) propyl] urea,  using according to the invention the N, N'-bis- [3- (dimethylamino) propyl] urea.

According to the invention, the second dimeric amine which includes the unsaturated rest presents the general formula:

5

in which R is defined as previously and E_ {u} represents the rest unsaturated

Preferably, E_ {u} is selected from The general formula groups:

6

in which M may be absent or is a C 1 -C 8 alkyl chain group linear, branched or cyclic, and each M can be identical or different, V may be hydrogen or a lower alkyl group, and each V it can be identical or different, Ar represents an aromatic nucleus or heteroaromatic, T may be absent or represents one or more substituents in the aryl nucleus, and Q may be absent or is a linkage group selected from ether, thioether, carbonyl, thione, secondary, tertiary or quaternary amine, sulfone or sulfoxide, or a C 1 -C 12 alkyl group of linear, branched or cyclic chain that may optionally contain in the alkyl chain one or more groups selected from ether, thioether, carbonyl, thione, alcohol, thiol, secondary amine, tertiary or quaternary, sulfone and sulfoxide

When E_ {u} includes an aromatic core, It is particularly preferred that E_ {u} be selected from between groups of general formula:

7

in which M, Q and T are as defined above and b represents the number of substituents T. (Substituents not specifically defined as T, M or Q they are hydrogen). The location of the substituents -M- in the aromatic (or heteroaromatic) core is preferably selected in such a way that it leads to sterically more substitution advantageous For a 6-member aromatic core, the groups -M- they can be ortho-, meta- or para-, but the orientation for.

When Ar is heteroaromatic, Ar represents preferably a 5 or 6 member aromatic core that includes one or more atoms of O and / or S and / or N.

In the preferred embodiments of the invention, T may be, for example, a lower alkyl, hydroxy, alkoxy, primary or secondary amine, primary alkylamine or secondary, carboxylic acid or halogen. In practice, the larger aryl diterciary amines are less useful due to the low solubility of the product in aqueous medium, but can solvents are used to achieve solubility in the reaction mixture.

These types of amine introduce the function unsaturated in the main polymer chain. Examples of these diterciary amines are N, N, N ', N'-tetramethyl-1,4-phenylenediamine, 4,4'-methylenebis-N, N-dimethylbencenamine, N, N, N ', N'-tetramethyl-3,3'-sulfonylbisbencenamine,  Y 2,6-bis [(dimethylamino) methyl] -4-methylanisola, being the N, N, N ', N'-tetramethyl-1,4-phenylenediamine particularly useful in the present invention.

In another embodiment of the invention, the second diterciary amine that includes the unsaturated rest presents The general formula:

8

in which R is defined as above and E_ {p} presents the formula general:

9

in which M is defined as previously, R '' 'can be identical to R' 'or it can represent a C 1 -C 8 straight chain alkyl group, branched or cyclic, and R '' can be selected between:

10

where V, T and b are as they have been defined above, Q may be absent or defined as above and Ar 'represents an aromatic nucleus or 5 or 6 member heteroaromatic. Group Q may be absent when, for example, R '' is derived from allyl chloride, but can be present when, for example, R '' is derived from allyl glycidyl ether. When Ar 'is heteroaromatic, Ar' preferably represents an aromatic nucleus with 5 or 6 members that includes one or more atoms of O and / or S and / or N.

In these embodiments of the invention, the unsaturated function is linked in a hanging fashion to the chain main polymer. This type of group in the polymer is achieved provided that the second diterciary amine used contains also a secondary amine function. If the total molar amount of binding agent is not in excess with respect to the molar amount Total amine or diterciary amines used, the amine function Secondary molecule does not participate in chain formation polymeric, since the binding agent reacts with the amine tertiary before the secondary amine. After completion the formation of the polymer chain, this amine group secondary can then be reacted with a compound  suitable unsaturated in order to produce an E_ {p} group unsaturated pendant

The invention discloses an additive for a Alkaline bath medium of zinc electrodeposition or alloy zinc, said additive comprising a random copolymer which It comprises the reaction product of:

(A) a prepolymer comprising the product of reaction of:

(i)

a or more diterciary amines that include an amide functional group or thioamide, and

(ii)

a or more second diterciary amines that include an amine group secondary, with

(iii)

one or more binding agents that can react with said amines (i) and (ii), with

(B) an unsaturated compound that can react with said secondary amine group in order to produce a group unsaturated pendant

Thus, the rest of the random copolymer comprising the reaction product of said secondary amine and The unsaturated compound most preferably has the formula:

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eleven

in which E_ {p} and R are as have been defined previously.

When the linking group does not contain a unsaturated function and the unsaturation required provide ( at least in part) diterciary amines of formula (4a) or (4b), the molar ratio r of (R '' + R '' ') with respect to the amine Secondary polymer chain can be 0 <r \ leq 2. Normally, this relationship is within the range 0.5 ≤ r ≤ 1.5. Thus, the amine functions secondary initially present in the polymer will become a mixture of tertiary and quaternary amine groups, and some of Secondary amine groups may remain unreacted.

Training examples of this are provided type of group in the use of N, N, N '', N '' - tetramethyldiethylenetriamine (as amine diterciaria which also includes a secondary amine function) reacted with benzyl chloride, 3,3'-imino-bis- (N, N-dimethylaminopropylamine) (as diterciary amine which also includes an amine function secondary) reacted with metalyl chloride, 3,3'-imino-bis- (N, N-dimethylaminopropylamine) (as diterciary amine which also includes an amine function secondary) reacted with allyl glycidyl ether and N, N, N '', N '' - tetramethyldiethylenetriamine (as amine diterciaria which also includes a secondary amine function) reacted with allyl chloride, the 3,3'-imino-bis- (N, N-dimethylaminopropylamine) as the second dimeric amine reacted with allyl glycidyl ether The most preferred combination.

In other embodiments of the invention, the second diterciary amine, when saturated, presents the General Formula:

12

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in which R is defined as above and E_s represents an alkyl group C 1 -C 8 straight-chain, branched or cyclic that may optionally contain in the alkyl chain one or more groups selected from: ether, thioether, carbonyl, thione, alcohol, thiol, secondary, tertiary or quaternary amine, sulfone and sulfoxide. When E_ {s} includes a tertiary amine or quaternary, E_ {s} can also be represented by formula general:

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13

in which M is defined as above and R '' 'represents an alkyl group C 1 -C 8 straight-chain, branched or cyclic The groups of formula (3a) or (3b) can be formed provided that the optional second diterciary amine contains also a secondary amine function. If the total molar amount of binding agent is not in excess with respect to the molar amount Total amine or diterciary amines used, the amine function secondary of the second optional diterciary amine does not participate in the formation of the polymer chain, since the binding agent reacts with the tertiary amine rather than the secondary amine. After completing the formation of the polymer chain, this secondary amine group can be reacted below with suitable precursors of R '' 'in order to produce groups with formulas (3a) or (3b). Depending on the amount of precursor of R '' 'used, the secondary amine functions can be convert to a tertiary amine (formula 3a) and / or an amine quaternary (formula 3b), and part of the secondary amine can remain without react.

They are preferred examples of the second amine diterciaria optional, when saturated, N, N, N ', N'-tetramethyl-1,6-diaminohexane,  bis- (2-dimethylaminoethyl) ether and 3,3'-imino-bis- (N, N-dimethylaminopropylamine).

A second optional diterciary amine particularly preferred is the N, N, N ', N'-tetramethyl-1,6-diaminohexane.  Alternatively, the optional second diterciary amine may be a dichloric cyclic amine, such as N, N'-dimethylpiperazine or triethylenediamine.

In another preferred embodiment of the invention, the first and / or second binding agent is unsaturated and presents the general formula:

14

in which X is Cl, Br or I, and G_ {u} represents a remainder unsaturated

Preferably, G_ {u} is selected from between

fifteen

where V represents H or a group lower alkyl, M 'is an alkyl group C 1 -C 8 straight-chain, branched or cyclic, and each M 'can be identical or different, Ar represents a aromatic nucleus with 5 or 6 members or a heteroaromatic nucleus with 5 or 6 members that includes one or more heteroatoms selected from between S and O, W may be absent or represents one or more substituents in the aromatic or heteroaromatic nucleus and Q 'can be absent or is a link group selected from ether, thioether, carbonyl, thione, sulfone or sulfoxide, or an alkyl group C 1 -C 8 straight-chain, branched or cyclic that may optionally contain in the alkyl chain one or more groups selected from ether, thioether, carbonyl, thione,  alcohol, diol, sulfone and sulfoxide

The location of the substituents -M'- in the aromatic core is preferably selected such that it gives place to sterically more advantageous substitution. For a core 6-member aromatic, the groups -M'- can be ortho-, meta- or for, but orientation for is preferred.

W may be, for example, a lower alkyl, hydroxyl, alkoxy, carboxylic acid or halogen. In practice, larger aryl compounds are less useful because of the low solubility of the product in aqueous medium, but may solvents are used to achieve solubility in the reaction mixture. Examples of this type of compound are 1,4-dichlorobutene, 1,4-dichlorobutino, and α, α'-dichloro-p-xylene, 1,4-dichlorobutene being the most preferred.

When G_ {u} includes an aromatic core, It is preferred that G_ {u} be selected from:

16

where W, Q 'and M' is defined as above and b represents the number of substituents W. (The substituents not specifically defined as W, Q 'or M' are hydrogen).

In an alternative embodiment preferred, the first binding agent is saturated and has the General Formula:

160

in which X represents Cl, Br or I, and G_s represents an alkyl group C 1 -C 8 straight-chain, branched or cyclic that may optionally contain in the alkyl chain one or more groups selected from ether, thioether, carbonyl, thione, alcohol, thiol, sulfone or sulfoxide. According to the invention, these Compounds are 1,3-dichlorobutane, 1,4-dichlorobutane, 1,5-dichloropentane, 1,6-dibromohexane, and bis-2-chloroethyl ether. They are Particularly preferred are 1,4-dichlorobutane and he bis-2-chloroethyl ether.

Alternatively, the first binding agent it can be a halomethyloxyran compound, for example epichlorohydrin

The random copolymer has the formula general:

17

in which 0 <x \ leq 1, 0 \ leq y <1, 0 \ leq z <1 y x + y + z = 1, n is so minus 2, A, B and R are defined as above, and J is a counterion G represents G_ {U} or G_ {s} as defined previously, E represents E_ {U} or E_ {s} as they have been defined above, and E_ {p} is defined as above, taking into account that if neither E_ {u} nor E_ {p} are present, G_ {u} must be present. Thus, x, y and z represent the molar fractions of the respective dimeric amines. The value absolute of n is not specified, since the polymer according to the invention will typically comprise polymeric molecules within a wide range of molecular weights. For polymeric molecules individual, n will generally be at least between 4 and 20, and It can reach up to 100 or more. The selection of the compounds used for the production of this copolymer is limited to defined in the claim one.

To reach the highest values of n, the molar ratio of total diterciary amines with respect to the binding agents may be in the range 5: 4 to 4: 5, but is very preferably about 1: 1.

In addition, the molar ratio in the polymer of the respective dimeric amine groups can be selected as desired in order to modify the properties of the electrodeposited coating produced by the products of the invention. When the bonding agent is unsaturated, only the dimeric amine with the amide functional group is essential, such that the optional second diterciary amine may be absent. When the second optional diterciary amine is present, it may be unsaturated or saturated. Preferably, the molar ratio in the dimeric amine polymer with the amide functional group with respect to the second optional diterciary amine is between 40:60 and 80:20, and more preferably between 50:50 and 70:30. In the case that only a saturated binding agent is present, a second diterciary amine must be present that includes an unsaturated moiety. Preferably, the molar ratio in the dimeric amine polymer with the amide functional group with respect to the second diterciary amine with an unsaturated moiety is between 40:60 and 80:20, and more preferably between 50:50 and 70:30 . The polymer according to the invention may include only saturated bonding agents, only unsaturated bonding agents or saturated and unsaturated binding agents, but it is essential that the unsaturation be provided, at least, by one of (a) the bonding agent and (b) a second amine
diterciaria.

The minimum degree of unsaturation that is desirable in the polymers according to the invention in order to achieve the desired properties will vary depending on the type of group or groups unsaturated present in the polymer (for example, as aromatic or aliphatic) and the way in which said unsaturated groups are present (for example, as they are in the polymer chain main or be hanging groups).

Generally, if M (A1) is defined as the molar fraction of diterciary amines that include the group functional amide, M (A2) is defined as the molar fraction of the second or second dimeric amines and M (G) is defined as the molar fraction of the binding agents, and M (A2) is can express as M (A2) = M (E_ {u}) + M (E_ {s}) + M (E_ {p}), M (G) can be express as M (G) = M (G_ {u}) + M (G_ {S}), and, when M (A1) + M (A2) + M (G) = 1, the degree molar of unsaturation M (U) in the polymer according to the invention It can be expressed as:

18

Thus, in the polymers according to the invention, 0 <M (U) <1, and higher values of M (U) indicate a higher unsaturation content. Preferably, M (U) is at least 0.05, plus particularly M (U) is between 0.1 and 0.5, and of particularly preferred form M (U) is comprised between 0.15 and 0.4.

According to the present invention, a aqueous alkaline medium zinc bath or zinc alloy for the deposition of zinc or zinc alloys comprising a source of zinc ions and, in the case of an alloy, a source of ions additional metal alloy metals, a chelating agent suitable for the purpose of making ions soluble and an amount Functional of the additive of the embodiments of the invention described above.

Preferably, the alloy metal is Select from iron, cobalt, nickel and manganese.

Preferably, zinc is present in an amount between 2 g / l and 50 g / l (expressed as zinc metal).

The alkalinity of the bath medium is preferably provided by sodium hydroxide or hydroxide of potassium in an amount between 10 and 300 g / l.

In preferred bathing media, the additive of the first or second aspects of the invention is present in an amount comprised between 0.01 g / l and 20 g / l, preferably between 0.1 g / l and 10 g / l, and particularly between 0.2 g / l and
5 g / l

Preferably, the preferred bathing media comprise an effective amount of one or more additive components additional selected from one or more of the groups that include:

A: silicates, tartrates, gluconates, heptates and other hydroxy acids;

B: N-benzylniacin, and / or aromatic aldehydes and their soluble bisulfite adducts in the medium bathing

C: amine / epihalohydrin polymers, particularly imidazole / epihalohydrin polymers.

An embodiment of the present invention discloses a method for electrodeposition of zinc or zinc alloys on a conductive substrate, which includes the stage that consists in contacting said substrate with the bathing medium according to the invention.

Preferably, the substrate is selected from between aluminum and its alloys, ferrous substrates, magnesium and its alloys, copper and its alloys, nickel and its alloys and zinc and Your alloys

Particularly preferably, the substrate It is steel, particularly mild steel.

The method according to the invention provides a random copolymer presenting the general formula:

19

in which 0 <x \ leq 1, 0 \ leq y <1, 0 \ leq z <1 y x + y + z = 1, n is so minus 2, A, B, R, E_ {p} and J are defined as above, G represents G_ {U} or G_ {s} as defined above and E represents E_ {U} or E_ {s} as defined previously, taking into account that if they are not present or E_ {u} or E_ {p}, G_ {u} must be present. The selection of compounds used for the production of this copolymer are restricts those defined in the claim one.

The following examples are illustrative of Preparation techniques for polymers according to the invention. Should it can be appreciated that in these examples it may not be attainable or 100% completion of the reaction is necessary, and that the time of Reflux can be varied accordingly.

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Example 1

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (35 grams), N, N, N ', N'-tetramethyl-1,4-phenylenediamine (15 grams), water (34 grams) and ethanol (47 grams) in a flask of reaction provided with reflux condenser, thermometer and stirrer. The reagents are stirred and heated to reflux. It adds slowly 1,4-dichlorobutane (31 grams) throughout 1.5 hours The mixture is allowed to reflux for 9 hours at 80-85 ° C. The resulting liquid is allowed to cool to room temperature, obtaining an aqueous solution of the product wanted.

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Example 2

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (36 grams), 3,3'-imino-bis- (N, N-dimethylaminopropylamine)  (17.6 grams) and water (103 grams) in a reaction flask provided of reflux condenser, thermometer and stirrer. The reagents are Shake and heat to reflux. It adds 1,4-dichlorobutane (31.8 grams) along 0.5 hours and the mixture is allowed to reflux for another 1.5 hours. TO then benzyl chloride (11.9 grams) is added throughout 0.5 hours and the mixture is allowed to reflux for an additional hour. Then sodium hydroxide (3.8 grams) is added as 50% solution. A new addition of benzyl chloride (5.9 grams) over 0.5 hours and the mixture It is allowed to reflux for another 2 hours. The resulting liquid is let cool to room temperature, obtaining a solution aqueous of the desired product.

Example 3

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (36 grams), 3,3'-imino-bis- (N, N-dimethylaminopropylamine)  (17.6 grams) and water (96 grams) in a reaction flask provided of reflux condenser, thermometer and stirrer. The reagents are Shake and heat to reflux. It adds 1,4-dichlorobutane (31.8 grams) along 0.5 hours and the mixture is allowed to reflux for another 1.5 hours. TO then allyl chloride (7.2 grams) is added along 0.5 hours and the mixture is allowed to reflux for an additional hour. TO sodium hydroxide (3.8 grams) is then added in the form of 50% solution. A new addition of allyl chloride (3.6 grams) over 0.5 hours and the mixture is let it reflux for another 2 hours. The resulting liquid is left refrigerate at room temperature, obtaining an aqueous solution of the desired product.

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Example 4

(Not according to the invention claimed herein document)

N, N'-bis- [3- (dimethylamino) propyl] urea (80.5 grams), N, N, N ', N'-tetramethyl-1,6-hexanediamine are introduced
(36.1 grams) and water (186.6 grams) in a reaction flask provided with reflux condenser, thermometer and stirrer. 1,4-Dichlorobutane (70 grams) is added over 1 hour. The mixture is allowed to reflux for another 4 hours. He
The resulting liquid is allowed to cool to room temperature, obtaining an aqueous solution of the desired product.

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Example 5

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (36 grams), 3,3'-imino-bis- (N, N-dimethylaminopropylamine)  (17.6 grams) and water (99 grams) in a reaction flask provided of reflux condenser, thermometer and stirrer. The reagents are Shake and heat to reflux. It adds bis-2-chloroethyl ether (35.8 grams) a over 1 hour and the mixture is allowed to reflux for another 1.5 hours. Then allyl chloride (7.2 grams) is added to the 0.5 hours long and the mixture is allowed to reflux for one hour additional. Then sodium hydroxide (3.8 grams) is added in the form of a 50% solution. Then a new one is made addition of allyl chloride (3.6 grams) over 0.5 hours and The mixture is allowed to reflux for another 2 hours. The liquid resulting is allowed to cool to room temperature, obtaining an aqueous solution of the desired product.

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Example 6

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (21.6 grams), 3,3'-imino-bis- (N, N-dimethylaminopropylamine)  (29.2 grams) and water (104.5 grams) in a reaction flask equipped with reflux condenser, thermometer and stirrer. The Reagents are stirred and heated to reflux. It adds bis-2-chloroethyl ether (35.8 grams) a over 1 hour and the mixture is allowed to reflux for another 1.5 hours. Then allyl chloride (11.9 grams) is added to it 0.5 hours long and the mixture is allowed to reflux for one hour additional. Then sodium hydroxide (6.2 grams) is added in the form of a 50% solution. Then a new one is made addition of allyl chloride (6.0 grams) over 0.5 hours and The mixture is allowed to reflux for another 2 hours. The liquid resulting is allowed to cool to room temperature, obtaining an aqueous solution of the desired product.

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Example 7

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (36 grams), 3,3'-imino-bis- (N, N-dimethylaminopropylamine)  (17.6 grams) and water (61 grams) in a reaction flask provided of reflux condenser, thermometer and stirrer. The reagents are Shake and heat to reflux. It adds 1,4-dichlorobutane (31.8 grams) over 1 hour and the mixture is allowed to reflux for another 2 hours. TO then allyl glycidyl ether (10.7 grams) is added throughout 0.5 hours and the mixture is allowed to reflux for 2 hours additional. The resulting liquid is allowed to cool to temperature ambient, obtaining an aqueous solution of the desired product.

The products of Example 1, Example 3, Example 5 and Example 7 are preferred embodiments of the present invention

Below are indicated, for purposes comparatives, examples of fully saturated polymers.

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Comparative example one

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (36 grams), 3,3'-imino-bis- (N, N-dimethylaminopropylamine)  (17.6 grams) and water (80 grams) in a reaction flask provided of reflux condenser, thermometer and stirrer. The reagents are Shake and heat to reflux. It adds 1,4-dichlorobutane (31.8 grams) over 1 hour and the mixture is allowed to reflux for another 2 hours. The liquid resulting is allowed to cool to room temperature, obtaining an aqueous solution of the desired product.

Comparative example 2

They are introduced N, N'-bis- [3- (dimethylamino) propyl] urea (36 grams), 3,3'-imino-bis- (N, N-dimethylaminopropylamine)  (17.6 grams) and water (80 grams) in a reaction flask provided of reflux condenser, thermometer and stirrer. The reagents are Shake and heat to reflux. It adds bis-2-chloroethyl ether (35.7 grams) a over 1 hour and the mixture is allowed to reflux for another 2 hours. The resulting liquid is allowed to cool to temperature ambient, obtaining an aqueous solution of the desired product.

Polymeric additives according to the present invention can provide excellent results in processes of zinc electrodeposition or zinc alloys when used individually. Additional advantages can be obtained through combination of the polymeric additive according to the invention with others known additives, such as those indicated in the following groups:

Group 1:

polymers according to the invention.

Group 2:

additives selected from the following: silicates, tartrates, gluconates, heptates and others hydroxy acids

Group number 3:

N-benzylniacin, and / or aldehydes aromatics and their bisulfite adducts soluble in the bathroom.

Group 4:

imidazole / epihalohydrin or other polymers amine / epihalohydrin polymers.

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Preferably, a compound of each group is present in the electrodeposition bath medium in an amount effective. Thus, bath formulations normally comprise: metallic zinc in the range 2-50 g / l, and more preferably 5-20 g / l; one or more metals alloy such as, but not limited to, nickel, iron, cobalt, manganese in an amount included, but not limited to it, between 0.005 and 10 g / l; sodium or potassium hydroxide in the range 10-300 g / l. The bathrooms for commercial use they also tend to absorb carbon dioxide from the atmosphere and, in consequently, they may contain varying amounts of carbonate of sodium or potassium

The polymers according to the invention are effective in concentrations between 0.01 and 20 g / l, but usually their concentration is between 0.1 and 10 g / l, and more preferably is between 0.2 and
5 g / l

The additives described in group 2, such as silicates, tartrates, gluconates, heptates or other hydroxy acids they are normally present in amounts comprised, although without be limited thereto, between 1 and 100 g / l, and more preferably between 20 and 80 g / l.

The additives described in group 3, such as N-Benzylniacin and aromatic aldehydes soluble in the bath (and its bisulfite adducts) are normally present in amounts included, but not limited to, between 1 and 500 mg / l, and more preferably between 5 and 100 mg / l.

The additives described in group 4 (imidazole / epihalohydrin polymers or other amine / epihalohi- polymers
drina) are normally present in amounts, although not limited thereto, between 0.01 and 20 g / l, and more preferably between 0.1 and 10 g / l.

Usually, bathrooms are operated at a temperature between 0 and 60ºC, although more preferably between 20 and 35 ° C.

The following examples are illustrative of zinc electrodeposition means and zinc alloys and of procedures using polymeric additives according to the present invention The following examples refer to electrodeposition experiments that were carried out on steels sweets, that is to say on a ferrous substrate. However, the procedures described in these examples are also suitable for electrodeposition on aluminum and its alloys, magnesium and its alloys, copper and its alloys, nickel and its alloys, and zinc and its alloys.

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Example A

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. An Hull cell trial of this electrolyte at 1 A for 10 minutes at a temperature of 25 ° C The resulting deposit was black and powdery, and was not Suitable for commercial use. 3 ml / l of the product was added formed in example 1 to the electrolyte. Now, a test at 1 A in Hull's cell resulted in a semi-gloss zinc deposit for current densities between 0.5 and 15 A / dm 2.

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Example B

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product of Example 2 was added to the electrolyte and a test was carried out at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C. A deposit was formed zinc semi-gloss for current densities between 1 and 15 A / dm 2.

Example C

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product of Example 3 was added to the electrolyte and a test was carried out at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C. A deposit was formed zinc semi-gloss for current densities between 1 and 15 A / dm 2.

Example D

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product of Example 4 was added to the electrolyte and a test was carried out at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C. A deposit was formed zinc semi-gloss for current densities between 1 and 4 A / dm 2.

Example E

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 2 ml / l of the product of Example 5 was added to the electrolyte and a test was carried out at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C. A deposit was formed zinc semi-gloss for current densities between 1 and 15 A / dm 2.

Example F

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 2 ml / l of the product of Example 7 and a 1 A test was carried out in Hull cell for 10 minutes at a temperature of 25 ° C. A semi-gloss deposit of zinc for current densities between 1 and 15 A / dm 2.

Example G

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product of Example 6 and a 1 A test was carried out in Hull cell for 10 minutes at a temperature of 25 ° C. A semi-gloss deposit of zinc for current densities between 2 and 15 A / dm 2.

Example H

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product was added to the electrolyte from example 1, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 8 g / l sodium silicate. A test at 1 A in Hull cell for 10 minutes at a temperature of 25ºC produced a completely bright and lustrous deposit in entire current density range of the cell panel from Hull. The thickness of the deposit obtained in said panel was measured using X-ray fluorescence, and the thickness of the deposit to 2 A / dm 2 was 10% higher, and at 4 A / dm 2 it was 12% higher, than that obtained from a comparative panel produced from an electrolyte prepared in the same way as before, but replacing an equivalent concentration of Mirapol (RTM) WT (a polymer such as that described in US Patent No. 5,435,898) by the product of example 1.

Example I

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product was added to the electrolyte from example 2, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 1 g / l sodium tartrate and potassium. A test at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C carried out on this electrolyte produced a completely bright and lustrous deposit throughout the interval of current densities of the Hull cell panel. The thickness of deposit obtained in said panel was measured using fluorescence X-ray, and the thickness of the deposit at 2 A / dm 2 was 34% higher, and at 4 A / dm 2 it was 56% higher, than that obtained from of a comparative panel produced from an electrolyte prepared in the same way as before, but replacing a equivalent concentration of Mirapol (RTM) WT per product of example 2.

Example J

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product was added to the electrolyte from example 3, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 8 g / l sodium silicate. A test at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C carried out on this electrolyte produced a deposit completely bright and lustrous throughout the interval of current densities of the Hull cell panel. Thickness of the deposit obtained in said panel was measured using X-ray fluorescence, and the thickness of the reservoir at 2 A / dm 2 it was 20% higher, and at 4 A / dm 2 it was 40% higher, than the obtained from a comparative panel produced from a electrolyte prepared in the same way as before, but replacing an equivalent concentration of Mirapol (RTM) WT with the product of example 3.

Example K

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product was added to the electrolyte from example 4, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 1 g / l sodium tartrate and potassium. A test at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C carried out on this electrolyte produced a completely bright and lustrous deposit in the interval of current densities between 0.4 and 5 A / dm 2.

Example L

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 2 ml / l of the product was added to the electrolyte from example 5, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 1 g / l sodium tartrate and potassium. A test at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C carried out on this electrolyte produced a completely bright and lustrous deposit throughout the interval of current densities of the Hull cell panel. The thickness of deposit obtained in said panel was measured using fluorescence X-ray, and the thickness of the deposit at 2 A / dm 2 was 16% higher, and at 4 A / dm 2 it was 33% higher than that obtained from of a comparative panel produced from an electrolyte prepared in the same way as before, but replacing a equivalent concentration of Mirapol (RTM) WT per product of example 2.

Example M

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product was added to the electrolyte from example 6, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 1 g / l sodium tartrate and potassium. A test at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C carried out on this electrolyte produced a completely bright and lustrous deposit throughout the interval of current densities of the Hull cell panel.

Example N

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product was added to the electrolyte from example 7, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 8 g / l sodium silicate. A test at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C carried out on this electrolyte produced a deposit completely bright and lustrous throughout the interval of current densities of the Hull cell panel. Thickness of the deposit obtained in said panel was measured using X-ray fluorescence, and the thickness of the reservoir at 2 A / dm 2 it was 17% higher, and at 4 A / dm 2 it was 35% higher, than the obtained from a comparative panel produced from a electrolyte prepared in the same way as before, but replacing an equivalent concentration of Mirapol (RTM) WT (a polymer such as that described in US 5,435,898) by the product of example 7.

Example O

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic),  135 g / l NaOH, 60 g / l sodium heptonate and 100 mg / l iron 3 ml / l of the product of the product was added to the electrolyte example 2, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF) and 0.02 g / l of N-Benzylniacin. A test at 1 A in Hull's cell for 10 minutes at a temperature of 25 ° C carried out in this electrolyte produced a completely bright and lustrous deposit over the entire range of current densities of the panel of the Hull cell. The passivation of the Hull cell panel in a chrome plating bath containing chromic acid, sulfuric acid, acid phosphoric and other inorganic salts produced a black coating uniform, indicating the uniform codeposition of iron along from the Hull cell panel.

Example P

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic),  135 g / l NaOH, 60 g / l sodium heptonate, 50 mg / l iron and 80 mg / l cobalt. 3 ml / l of the product was added to the electrolyte from example 2, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF) and 0.02 g / l of N-Benzylniacin. A test at 1 A in Hull's cell for 10 minutes at a temperature of 25 ° C carried out in this electrolyte produced a completely bright and lustrous deposit over the entire range of current densities of the panel of the Hull cell. The passivation of the Hull cell panel in a chrome plating bath containing chromic acid, sulfuric acid, acid phosphoric and other inorganic salts produced a black coating uniform, indicating cobalt and iron uniform codeposition along the panel of Hull's cell. The subsequent analysis of deposit by X-ray analysis of energy dispersion gave as result a cobalt concentration of 0.4% over a wide range of current densities.

Example Q

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 3 ml / l of the product was added to the electrolyte from example 3, 0.5 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.1 g / l veratraldehyde (3,4-dimethoxybenzaldehyde) and 1 g / l tartrate sodium and potassium A test at 1 A in Hull cell for 10 minutes at a temperature of 25 ° C carried out on this electrolyte produced a bright but slightly diffuse deposit throughout the current density range of the cell panel Hull

Example R

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 1.5 ml / l of the product was added to the electrolyte from example 1, 1.0 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.02 g / l of N-benzylniacin and 8 g / l sodium silicate. Be conducted a test at 4 A in Hull's cell for 45 minutes at a temperature of 25 ° C, and after electrodeposition the panel was passivated in a chromium plating bath containing chromic sulfate, acid hydrofluoric, nitric acid and other inorganic salts, and a then dried. The trial produced a bright deposit in entire current density range of the cell panel of Hull, and after keeping it for 2 months the deposit does not He had blisters.

Example S

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 1.5 ml / l of the product was added to the electrolyte from example 7, 1.0 ml / l of an imidazole / epichlorohydrin polymer (Lugalvan (RTM) ES 9572, from BASF), 0.01 g / l of N-benzylniacin, 0.02 g / l of vanillin and 8 g / l of sodium silicate A 4 A test was carried out in Hull's cell for 45 minutes at a temperature of 25 ° C, and after electrodeposition the panel was passivated in a chrome plating bath that it contained chromic sulfate, hydrofluoric acid, nitric acid and other inorganic salts, and then dried. Essay produced a bright deposit across the entire density range of Hull cell panel current, and after saving for 2 months the deposit showed no blisters. In an essay equivalent, substituting the product of comparative example 1 for the product of example 7, after 3 days blisters appeared in the test panel. In an equivalent trial, replacing the product of comparative example 2 by the product of example 7, after being stored for 2 months the deposit did not show blisters, but the brightness of it had been reduced. In an essay equivalent, replacing the Mirapol (RTM) WT with the product of example 7, after keeping the deposit for 2 months had blisters, but the brightness and thickness had been reduced of the same.

Example T

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 1.0 ml / l of the product was added to the electrolyte from example 1, 1.0 ml / l of an imidazole / epichlorohydrin polymer, 0.02 g / l of N-benzylniacin and 8 g / l of silicate sodium. An object was subjected to electrodeposition in the electrolyte of steel with an average cathodic current density of 2.5 A / dm 2 for 30 minutes at a temperature of 25 ° C. After the electrodeposition, the object was passivated in a chrome plating bath that It contained chromic sulfate, hydrofluoric acid, nitric acid and others inorganic salts, and then dried. The object was coated completely with a shiny and glossy zinc deposit, and after storing it for 2 months the deposit did not show blisters

Example U

An aqueous electrolyte suitable for zinc electrodeposition containing 13 g / l zinc (metallic) and 130 g / l NaOH. 3.0 ml / l of the product was added to the electrolyte from example 1, 1.0 ml / l of an imidazole / epichlorohydrin polymer, 0.015 g / l of N-benzylniacin and 8 g / l of silicate sodium. An object was subjected to electrodeposition in the electrolyte of steel with an average cathodic current density of       2.5 A / dm 2 for 1 hour at a temperature of 25 ° C. After electrodeposition, the object was passivated in a bath of chromium plating containing chromic sulfate, hydrofluoric acid, acid nitric and other inorganic salts, and then dried. He object was completely coated with a glossy zinc deposit, and after keeping it for 10 months the deposit did not show blisters The deformation of the piece showed that the Deposit adhesion was excellent.

Example V

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 1.5 ml / l of the product was added to the electrolyte from example 3, 1.0 ml / l of an imidazole / epichlorohydrin polymer, 0.02 g / l of N-benzylniacin and 8 g / l of silicate sodium. An object was subjected to electrodeposition in the electrolyte of steel with an average cathodic current density of 2.5 A / dm 2 for 40 minutes at a temperature of 25 ° C. After the electrodeposition, the object was passivated in a chrome plating bath that It contained chromic sulfate, hydrofluoric acid, nitric acid and others inorganic salts, and then dried. The object was coated completely with a glossy zinc deposit, and after keep it for 2 months the deposit did not show blisters.

W example

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 1.5 ml / l of the product was added to the electrolyte from example 1, 1.0 ml / l of an imidazole / epichlorohydrin polymer, 0.02 g / l of N-benzylniacin and 8 g / l of silicate sodium. A panel was electroplated to the electrolyte of steel covered with a standard roughness with a density of average cathodic current of 2.5 A / dm 2 for 60 minutes at a temperature of 25 ° C. After electrodeposition, the panel was passivated in a chromium plating bath containing chromic sulfate, acid hydrofluoric, nitric acid and other inorganic salts, and a then dried. The thickness of the deposit was 27 µm (measured by X-ray fluorescence). The surface roughness of panel was analyzed before and after electrodeposition by a laser interferometry technique, and the result was expressed as the average deviation of the surface profile from the line central (Ra). Before electrodeposition, the roughness of surface area was Ra = 1.10 µm, and after the electrodeposition said surface roughness was Ra = 0.64 \ mum. A comparative panel produced from an electrolyte prepared in the same way as before but replacing a equivalent concentration of Mirapol (RTM) WT per product of Example 1 produced a Ra = 1.10 before electrodeposition and Ra = 1.00 after it.

Example X

An aqueous electrolyte suitable for zinc electrodeposition containing 12 g / l zinc (metallic) and 135 g / l NaOH. 1.5 ml / l of the product was added to the electrolyte from example 3, 1.0 ml / l of an imidazole / epichlorohydrin polymer, 0.02 g / l of N-benzylniacin and 8 g / l of silicate sodium. A panel was electroplated to the electrolyte of steel covered with a standard roughness with a density of average cathodic current of 2.5 A / dm 2 for 55 minutes at a temperature of 25 ° C. After electrodeposition, the panel was passivated in a chromium plating bath containing chromic sulfate, acid hydrofluoric, nitric acid and other inorganic salts, and a then dried. The thickness of the deposit was 25 µm (measured by X-ray fluorescence). The surface roughness of panel (measured by laser interferometry) was Ra = 1.10 µm before electrodeposition and Ra = 0.71 µm after same.

Claims (9)

1. Procedure for preparing a medium Alkaline bath electrodeposition zinc or zinc alloy, which comprises the following stages: (A) prepare a random copolymer additive which comprises a reaction product of:

(i)

a or more diterciary amines containing an amide functional group or thioamide, in which said one or more amines are selected diterciarias from among the group constituted by N, N'-bis [2-diethylaminoethyl] urea Y N, N'-bis- [3- (dimethylamino) propyl] urea;

(ii)

a or more second diterciary amines comprising a residue unsaturated, selected from the group consisting of N, N, N ', N'-tetramethyl-1,4-phenylenediamine, 4,4'-methylenebis-N, N-dimethylbencenamine, N, N, N ', N'-tetramethyl-3,3'-sulfonylbisbencenamine,  Y 2,6-bis [(dimethylamino) methyl] -4-methylanisola, or a reaction product of one or more second dimer amines which include a secondary amine group together with a compound unsaturated that can react with the secondary amine group to produce a pendant unsaturated group, selecting the reaction product from the group consisting of N, N, N '', N '' - reacted tetramethyldiethylenetriamine with benzyl chloride, 3,3'-imino-bis- (N, N-dimethylaminopropylamine) reacted with metalyl chloride, allyl glycidyl ether, or chloride of benzyl, and N, N, N '', N '' - tetramethyldiethylenetriamine reacted with allyl chloride, with

(iii)

one or more binding agents that they can react with said one or more diterciary amines and said one or more second dimeric amines, or the reaction product of said one or more diterciary amines that include an amine group secondary together with an unsaturated compound, wherein said one or more binding agents are selected from the group consisting of epichlorohydrin, selected unsaturated compounds  from among the group consisting of 1,4-dichlorobutene, 1,4-dichlorobutino, and α, α'-dichloro-p-xylene,  and saturated compounds selected from the group constituted by 1,3-dichlorobutane, 1,4-dichlorobutane, 1,5-dichloropentane, 1,6-dibromohexane, and bis-2-chloroethyl ether; Y

(B) combine the reaction product of the step (A) with a source of zinc ions and, in the case of the alloy, a source of additional metal ions of alloy metals and a suitable chelating agent to make the ions soluble with the in order to produce an alkaline electrodeposition bath medium of zinc or zinc alloy. 2. Method according to claim 1, in which the alloy metal is selected from among iron, cobalt, nickel and manganese. 3. Method according to claim 1 or 2, wherein zinc is present in an amount of 2 g / l at 50 g / l, expressed as metallic zinc. 4. Procedure according to any of the claims 1 to 3, wherein the alkalinity is provided by sodium hydroxide or potassium hydroxide in an amount of 10 at 300 g / l. 5. Procedure according to any of the claims 1 to 4, wherein the additive is present in a amount from 0.01 g / l to 20 g / l, preferably 0.1 g / l to 10 g / l, and particularly 0.2 g / l at 5 g / l. 6. Procedure according to any of the claims 1 to 5, further comprising the addition of a effective amount of one or more additional additive components selected from one or more of the groups comprising:

TO:

silicates, tartrates, gluconates, heptates and other hydroxy acids;

B:

N-Benzylniacin, and / or aromatic aldehydes and their soluble bisulfite adducts in the medium bathing

C:

amine / epihalohydrin polymers, particularly imidazole / epihalohydrin polymers.

7. Procedure for electrodeposition of zinc or zinc alloys on a conductive substrate, comprising  said procedure the steps that consist of preparing a medium bath according to the procedure according to any of the claims 1 to 6 and contacting said substrate with the half bath 8. Method according to claim 7, in which the substrate is selected from aluminum and its alloys,  ferrous substrates, magnesium and its alloys, copper and its alloys, nickel and its alloys, and zinc and its alloys. 9. Method according to claim 8, in which the substrate is steel, in particular mild steel.